This invention relates, in general, to data processing within a computing environment and, in particular, to reconfiguring structures within a shared facility of the computing environment.
One example of a shared facility is the coupling facility offered by International Business Machines Corporation. The coupling facility is a shared external storage processor that contains storage accessible by one or more processors coupled to the coupling facility and performs operations requested by the programs in those processors. Data and controls to be shared are stored in storage structures within the coupling facility. In one example, these storage structures include cache, list and/or lock structures.
It is desirable, and sometimes necessary, to reconfigure one or more of the storage structures. For example, it may be desirable or necessary to change the characteristics of a structure or to move the structure from one coupling facility to another coupling facility. If such a reconfiguration is necessary, then it is imperative that it be performed in a manner that is least disruptive for the users of the structure.
Previous attempts have been made to provide capabilities that enable reconfiguration of storage structures of a coupling facility. However, a need still exists for a reconfiguration technique that is minimally disruptive to the users of the structures, is simple from the users"" perspective, and is mostly transparent to the users. A further need exists for a capability that facilitates the operation of the reconfiguration, particularly in those sysplexes where there are numerous structures and users of those structures. A need exists for a reconfiguration capability that is controlled by the operating system, rather than the users.
The shortcomings of the prior art are overcome and additional advantages are provided through the provision of a method of modifying storage structures within a shared storage processor of a computing environment. The shared storage processor is coupled to one or more processors of the computing environment, and the method includes, for instance, specifying one or more target maximum counts to be used in modifying a storage structure in the shared storage processor; and modifying the storage structure using the one or more target maximum counts.
In a further aspect of the present invention, a system of modifying storage structures within a shared storage processor of a computing environment is provided. The shared storage processor is coupled to one or more processors of the computing environment, and the system includes, for instance, means for specifying one or more target maximum counts to be used in modifying a storage structure of the shared storage processor; and means for modifying the storage structure using the one or more target maximum counts.
In yet a further aspect of the present invention, at least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform a method of modifying storage structures within a shared storage processor of a computing environment is provided. The shared storage processor is coupled to one or more processors of the computing environment, and the method includes, for instance, specifying one or more target maximum counts to be used in modifying a storage structure of the shared storage processor; and modifying the storage structure using the one or more target maximum counts.
The present invention advantageously provides a structure modification technique (i.e., expansion, contraction and reapportion) that enables a structure to be modified using target maximum counts. In one example, the modification capability is controlled by the operating system, and thus, facilitates exploitation by the users of the structures. Further, the modification capability allows previously allocated structures to be modified to satisfy new and pending requests.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention.